1. Field of the Invention
This invention relates to methods of fabricating a semiconductor package, and, more particularly, to a method of fabricating a semiconductor package having a heat dissipating structure.
2. Description of Related Art
A modern electronic product is compact-sized and low-profiled. With the rapid development of a semiconductor fabrication process, more and more electrical elements are allowed to be integrated into a chip. However, the electronic elements, when in operation, generate a great amount of heat, and the heat cannot be dissipated to a region outside of the chip because the encapsulant does not have well enough heat dissipating quality. Accordingly, the lifespan of the electronic elements is reduced. Therefore, how to dissipate the heat generated by the electronic elements effectively is an important issue in the art. In general, a heat dissipation is disposed above the chip to dissipating the heat generated by the chip to an ambient environment.
According to the prior art, a compression molding method is used during a packaging process, to disposed a heat dissipation on a chip, as shown in FIGS. 1A to 1D, which illustrate a method of fabricating a semiconductor package 1 according to the prior art.
As shown in FIG. 1A, a heat dissipation 11 is disposed on a side in a mold 10, and in physical contact with a surface of the mold 10.
As shown in FIG. 1B, a substrate 12 having a plurality of semiconductor elements 12 disposed thereon is disposed on another side in the mold 10 (i.e., an upper portion 101), and the semiconductor elements 121 are disposed between the substrate 12 and the heat dissipations 11. The semiconductor element 121 is electrically connected via a plurality of bonding wires 120 to the substrate 12.
As shown in FIG. 1C, an encapsulant 13 is then formed in a mold cavity 100 of the mold 10 to encapsulate the semiconductor element 121.
As shown in FIG. 1D, a singulation process (along a cutting path S) are performed after the encapsulant 13 is released from the mold 10, to form a plurality of semiconductor packages 1.
In the method according to the prior art, the heat dissipations 11 are not closely adhered to the mold 10. Accordingly, during the formation of the encapsulant 13, the encapsulant 13 will flow via a side of the heat dissipation 11 to an external surface of the heat dissipation 11 due to a capillarity phenomenon. In other words, a resin bleed phenomenon happens. After the encapsulant 13 is released from the mold 10, a residual encapsulant 13′ still stays on the external surface of the heat dissipations 11, as shown in FIG. 1 D′, and a semiconductor package 1′ of poor quality is formed.
Therefore, how to overcome the problems of the prior art is becoming an urgent issue in the art.